#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

ifstream fin("lca.in");
ofstream fout("lca.out");

#define Nmax 100005

int n, m, x, y, k;
int Rmq[4 * Nmax][20], L[2 * Nmax], Log[2 * Nmax], H[2 * Nmax], First[Nmax];
vector<int> G[Nmax];

void Process() {
    Rmq[1][0] = 1;
    for(int i = 2; i <= k; ++i) {
        Log[i] = Log[i / 2] + 1;
        Rmq[i][0] = i;
    }

    int p;
    for(int j = 1; (1 << j) < k; ++j)
        for(int i = 1; i + (1 << j) <= k; ++i) {
            p = 1 << (j - 1);

            Rmq[i][j] = Rmq[i][j - 1];
            if(L[Rmq[i + p][j - 1]] < L[Rmq[i][j]])
                Rmq[i][j] = Rmq[i + p][j - 1];
        }
}

int Query(int x, int y) {
    x = First[x];
    y = First[y];
    if(x > y) {
        int aux = x;
        x = y;
        y = aux;
    }

    int diff = y - x + 1;
    int lg = Log[diff];
    int sol = Rmq[x][lg];

    if(L[sol] > L[Rmq[y - (1 << lg) + 1][lg]])
        sol = Rmq[y - (1 << lg) + 1][lg];

    return H[sol];
}

void Dfs(int nod, int val) {
    H[++k] = nod;
    L[k] = val;
    First[nod] = k;

    for(int y : G[nod]) {
        Dfs(y, val + 1);
        H[++k] = nod;
        L[k] = val;
    }
}

int main()
{
    fin >> n >> m;
    for(int i = 2; i <= n; ++i) {
        fin >> x;
        G[x].push_back(i);
    }

    Dfs(1, 0);
    Process();

    for(int i = 1; i <= m; ++i) {
        fin >> x >> y;
        fout << Query(x, y) << '\n';
    }
    return 0;
}